The Keystone Conference entitled "Membrane Protein Structure and Mechanism" will meet February 4-9, 2003 in Taos, New Mexico. The conference will feature presentations by both established and beginning investigators in the rapidly advancing field of membrane proteins. Approximately 30% of the human genome may encode transmembrane and peripheral membrane proteins which are critical to the regulation and function of most cellular signaling pathways and metabolic systems. Moreover, most current pharmaceutical agents are directed toward membrane proteins. Yet progress toward a molecular understanding of membrane protein structure and mechanism has been comparatively slow until recent years. Currently, a wide array of sophisticated physical, chemical and biochemical methods have begun to elucidate basic structural and mechanistic features of the major functional subclasses of membrane proteins, including transmembrane channels, receptors, transporters, and peripheral membrane proteins. The proposed meeting is unique, since no other conference of this size brings together leading researchers focusing on all the major classes of membrane proteins to compare their latest findings, discuss current controversies, and disseminate their newest experimental approaches. Moreover, the small size and informal format of the meeting encourages interactions between senior investigators, beginning investigators, postdocs and students, thereby providing a valuable training environment. Participants in the meeting will see, in many cases for the first time, presentations describing recently solved high resolution structures of a transmembrane anion channel, a membrane-spanning chemotaxis receptor, an ABC transmembrane transporter, and multiple peripheral membrane proteins. Other presentations will describe the structural and chemical events that occur as membrane proteins cycle between different functional states including opened/closed, on/off, inward/outward-facing, bound/free. Overall, the conference will provide a forum in which membrane protein researchers come together to present exciting new results with broad, significant implications for membrane protein structure and mechanism.